The invention relates to a suction gripper for transferring ophthalmic lenses, in particular contact lenses, from a storage cup into a centering cup, a manipulation system for ophthalmic lenses with such a suction gripper, as well as the use of such a suction gripper for transferring ophthalmic lenses from a storage cup to a centering cup.
Ophthalmic lenses such as intraocular lenses and in particular contact lenses of plastic material are usually cast in a mold and after removal from the casting mold are stored in a storage cup for further manipulation.
As an example for ophthalmic lenses and similar objects, reference is being had to contact lenses in the following. The storage cup is significantly larger than the contact lens that is intermediately stored therein so that the contact lens is located therein in an undefined position. From this undefined position, the moist contact lenses must be gripped and transferred into the final packaging. For gripping and transferring contact lenses, suction grippers are known that can grip the contact lens by suction and in the suction-secured state can transport the lens to the target location. The final packaging of the contact lens is however only insignificantly larger than the nominal size of the contact lens. In order for the contact lens to be placed properly into the target packaging, the suction gripper provided for this purpose must be sufficiently small in order to be insertable together with the contact lens adhering thereto into the target container.
In order to secure by suction a contact lens with such a small suction gripper and in order to be able to lift it, an exact mutual positional alignment of contact lens and suction gripper is required. As has been discussed above, such an exact positional alignment is however not provided in connection with an oversized storage cup, i.e., a storage cup that is significantly larger in comparison to the final packaging. The disordered random position of the contact lenses in the storage cup correlated therewith has the result that the inserted suction grippers that are inserted in an automated process cannot, or cannot reliably, attract and grip by suction the contact lenses provided in the storage cup.
A further problem in regard to the manipulation of such contact lenses is that they may not dry out and therefore must be kept moist at all times. Appropriate manipulation devices must therefore be capable of gripping and transporting the contact lenses in the moist or wet state. In this context, attention must be paid that transfer of liquid that is utilized during manipulation into the packaging container is avoided. Moreover, the contact lenses are flexible. It must therefore be avoided that the contact lenses are overextended or folded over during handling.